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<table width="100%" summary="page for meh"><tr><td>meh</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Data from 2010 horse mackerel and mackerel egg survey</h2>

<h3>Description</h3>

<p> The data relate to the distribution of horse mackerel (<code>meh</code>, Trachurus trachurus) eggs and mackerel (<code>med</code>, Scomber scombrus) eggs and were collected as part of the 2010 mackerel survey aimed at assessing the mackerel spawning stock biomass using the daily egg production method. </p>


<h3>Usage</h3>

<pre>
data(med)
data(meh)
</pre>


<h3>Format</h3>

<p> A data frame with the following columns. Each row corresponds to one sample of eggs. 
</p>

<dl>
<dt>count</dt><dd><p>The number of stage I eggs in this sample.</p>
</dd>
<dt>la</dt><dd><p>sample station latitude</p>
</dd>
<dt>lo</dt><dd><p>sample station longitude</p>
</dd>
<dt>vol</dt><dd><p>volume of water sampled</p>
</dd>
<dt>T.surf</dt><dd><p>surface temperature in centigrade</p>
</dd>
<dt>T.x</dt><dd><p>temperature at x metres depth.</p>
</dd>
<dt>T1.x</dt><dd><p>Second temperature measurements.</p>
</dd>
<dt>Sal20</dt><dd><p>Salinity at 20m depth</p>
</dd>
<dt>b.depth</dt><dd><p>seabed depth in metres for <code>med</code> only.</p>
</dd>
<dt>lon</dt><dd><p>The longitude of the sample station in degrees east.</p>
</dd>
<dt>lat</dt><dd><p>The latitude of the sample station in degrees north.</p>
</dd>
<dt>time</dt><dd><p>The time of day (in hours) at which the sample was taken.</p>
</dd>
<dt>salinity</dt><dd><p>The salinity (saltiness) of the water at the sampling location.</p>
</dd>
<dt>period</dt><dd><p>sampling period</p>
</dd>
<dt>country</dt><dd><p>Country responsible for sample</p>
</dd>
<dt>ship</dt><dd><p>Vessel ID</p>
</dd>
<dt>DT</dt><dd><p>sample data and time</p>
</dd>
<dt>ID</dt><dd><p>Sample ID</p>
</dd>
<dt>gear</dt><dd><p>type of sampling gear used</p>
</dd>
</dl>

<p>The remaining fields are undocumented.
</p>


<h3>Details</h3>

<p>The original data files do not always exactly match the file documentation, so these data should not be treated as definitive.  
</p>


<h3>Source</h3>

<p>ICES Eggs and Larvae Dataset 2012, ICES, Copenhagen
</p>
<p><a href="http://www.ices.dk/">http://www.ices.dk/</a>
</p>
<p><a href="http://eggsandlarvae.ices.dk/Download.aspx">http://eggsandlarvae.ices.dk/Download.aspx</a>
</p>


<h3>Examples</h3>

<pre>
require(gamair)
par(mfrow=c(1,2))
data(meh);data(med);data(coast)
# plot the egg counts against location
plot(meh$lo,meh$la,cex=0.2+meh$count^.5/10,col="grey",
     pch=19,xlab="lo",ylab="la",main="horse mackerel")
ind &lt;- meh$count==0
points(meh$lo[ind],meh$la[ind],cex=0.1,pch=19)
lines(coast)

# same for med
plot(med$lo,med$la,cex=0.2+med$count^.5/10,col="grey",
     pch=19,xlab="lo",ylab="la",main="mackerel")
ind &lt;- med$count==0
points(med$lo[ind],med$la[ind],cex=0.1,pch=19)
lines(coast)

</pre>


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